Telephone system



A. WASCH NACK TELEPHONE SYSTEM Filed Marc 1924 '3 sheets Sheet 1 flab I21 Maschnaek Aug. 28, 1928.

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A. WASCHNACK TELEPHONE SYSTEM Filed fua'rch 1.1924 3 Shets-Shet 557'nuen mr En ol 0Z7 Hachnck Patented Aug. 28, 1928.

UNITED STATES PATENT OFFICE.

ADOLF' WASCHNACK, OF NEU FINKENKRUG, GERMANY, ASSIGNOR TO SIEMENS &HALSKE AKTIENGESELLSCHAFT, WERNERWERK, F SIEMENSSTADT, NEAR BER- LIN,GERMANY.

TELEPHONE SYSTEM.

Application filed March 1, 1924, Serial No.

The invention relates to automatic telephone systems and moreparticularly to a circuit arrangement for switches having movement inone direction and having several groups of contacts, over whichsubscribers lines can be reached by one or more trains of impulses.

I The invention consists in that over certain contact groups connectionsare set up with lines leading to subscribers lines and over other groupswith lines leading to succeeding connecting devices which may beoperated in any manner desired, and after the wipers have been set bynumber impulses on a line leading to a succeeding connecting device, theswitching means, e. side switch, of the switch is so influenced thatswitching operations are prevented, which take place when a subscribersline is taken into use, for example ringing, and that the positioningdevices of the switch are withdrawn, from the influence of furthernumber impulses transmitted by the calling party.

.Thedrawings comprisingFigs. 1, 2 and 3 show diagrammatically by way ofexample one embodiment of the invention.

In Fig. 1, a substation Tn, a finder switch AS, and the controllingrelays of a selector switch LIV are shown.

In Fig. 2, the wipers and operating magnet of switch LIV, the test relayT1 of an individual line, and the hunting swltch AII are shown. I

In Fig. 3, the side switch of the selector switch LIV is shown. I

1 The subscriber Tn is connected to an exchange, in which connectionscan be set up by means of finder switches, e. g., AS, which areautomatically operated on the initiation of a call and are common to anumber of sub- 40 seribers, and by means of selector switches e. LIV,which are operated by number 1mpulses. The bank contacts of the switchLIV are divided into a number of groups TG, VG and RG. Subscribers ofthe local exchange are reached over the first group of contacts TG,while trunk lines such as VL, VLl, leading to some succeeding connectingdevice e. g. switch AI/V, are reached over the second group 01 contactsVG. The third group of contacts comprises contacts upon which the switchcome to rest and will remain under the influence of the callingsubscriber, if it is necessary to transmit more than one train ofimpulses for setting up a connection 696,130, and in Germany March 29,1923.

to lines in the first or second contact group. The switches AS and LIVare set and the other switching operations required for establishing aconnection such as testing, ringing and switching through, are effectedwith the assistance of an auxiliary switch known as a side-switch.

The setting up of a local connection will first be described. Thesubscriber Tn requlring such a connection lifts his receiver, whereuponthe relay An common to all the subscribers ol the exchange operates:earth, battery, winding of the relay An, back contact If, lead a,subscribefls station Tn, lead 6, back contact 151, earth. The relay Ancompletes a circuit for the relay K: earth, battery, winding of therotary magnet D of the switch LIV, wiper (Z2, normal contact d4, windingI of the relay K, side switch arm IV in position 1, front contact (m8,earth. The rotary magnet D1 of the switch LIV does not operate in thiscircuit owing to the resistance of the relay K. The relay K, however,operates and closes a circuit for the relay F earth, battery, resistancewe, winding of the relay F, side switch arm IIIin position I, doubleworking contact k5, winding II of the relay K, earth. The relay F byclosing its contact f6 connects up the side switch magnet ST: earth,battery, winding ST, front contact f6, earth, so that the side switchtakes one step and moves into position 2. The relay F is short-circuitedat the contact stT of the side switch magnet ST, so that it releases andcauses the contact f6 to open the circuit of the side switch ma net ST.In position 2 of the side switch, t 1e relay interrupter RU is connectedto the rotary magnet D of the switch AS: earth, battery, winding D, sideswitch arm III in position 2, double back contact 08, relay interrupterRU, earth. The switch AS thereupon rotates its wipers 7M9, [0e10, lcall,lca12 until they engage with the contacts connected to the line of thecalling subscriber. Thereupon a circuit is established for the relay C:earth, battery, resistance @013, front contact kll,

winding of the relay C, side switch arm II in position 2, wiper 7ca9,back contact it, lead a, subscribers station Tn, lead 6, back contactt1, earth. The relay C at its double back contact 08 disconnects therotary magnet D of the switch AS, and furthermore, by closing its doublefront contacts 015 and 016 estal lishes the feeding bridge: earth,battery, re-

sistance @013, double front contact 015, winding I of the relay A, backcontact n17, wiper AaalO, lead a, subscribers station Tn, lead 5, wiperball, back contact n18, winding II of the relay A, double front contact016, earth. Upon the operation of therelay a which now takes place, anew holding circuit is established for the relay C, as this is directlyearthed by the contact n19 instead of over the subscribers line andinstrument as hitherto. At the double front contact 016, a circuit is established for the relay T of the calling subscriber as follows: earth,battery, winding of,

the relay T, lead 0, wiper 7m12, double front contact 016, earth. RelayT operates and in known manner marks the calling subscribers lineengaged to incoming calls. Relay T also by opening its contacts 1? andt1, disconnects the relay An, which thereupon at its contact (m3 opensthe circuit of the relay K. The relay A at its front contact e20connects earth to the relay F: earth, battery, resistance 7.04:, Windingof the relay F, side switch arm V in position 2, front contact 0020,earth. The relay F connects up the side switch magnet, whereupon theside switch moves into the position 3, in which it is again disconnectedby the short circuiting of the relay F. The relay V is energized inposition '3: earth, battery, winding II of the relay V, bank contact d5,wiper 7x026, side switch arm II in position 3, front contact (620,earth. Over the side switch arm I in position 3, the relay F is againenergized and connects up the side switch magnet ST, whereupon the sideswitch moves into position 4 and is there disconnect ed owing to therelay F being short circuited by the contact st7. The relay V howeverremains energized in the circuit: earth, battery, winding II of therelay V, bank contact 615, wiper ZmQG, side switch arm II in position 4,resistance c021, front'contact 020, earth;

' In position at of the side switch, the calling subscriber transmitsimpulses by means of his dial for setting the switch LIV on the contactof the wanted subscriber During impulse transmission the circuit ofrelay A is interrupted a number of times corresponding to the numberdialled: in consequence the front contact @531 is opened and closed asimilar number of times and a circuit is estab- -1ishcd each time overthe front contact tion 4, winding I of the relay V, earth. Since therelay V is made slow acting, it does not release when the back contactn28 is opened during impulse transmission, and thus maintains theimpulsing circuit at contact @223 and 'at contact 2 22 presents themoving on of the side switch. The relay C is rendered slow acting whenits winding is short cireuited over the back contact 128 and the frontcontacte27, hence it does not release during im pulse transmission.

If only one train of impulses is required for reaching the wantedsubscriber, then, as soon as the wipers of the switch LIV are set on thecontacts of the wanted subscribers line and the relay V hasole-energized, the testing ofthe line and the ringing of the wantedsubscriber take place and also the switching through of the calling andcalled lines after the wanted-subscriber has answered.

If, however, more than one train of impulses is required for reachingthe wanted subscriber, the wipers of the switch LIV are set on one ofthe contacts in the contact group RG which may be called rest contacts.In this case the relay V is main tained energized in order that furtherimpulses generated by the calling subscribers dial may be transmitted tothe rotary magnet D1 of the switch LIV. The circuit for the relay V nowextends as follows: earth, battery, winding II of the relay V, restcontact, e. g. rg, wiper M626, side switch arm II in position 4,resistance 1021, front contact (120, earth. The calling subscriber willnow transmit a further train of impulses which operate as before toadvance the wipers 706624, 766625 and 7ca26, so that the latter standsfor instance on the contact in. When relay V now de-energizes at the endof this train of impulses, a circuit is completed for the relay F overthe back contact @221 earth, battery, resistance 104i, winding of therelay F, side switch arm I in position at, back contact 2222, earth. Therelay F operates and causes the side switch magnet ST to be connected'upso that the side switch moves into the position 5, whereupon the magnetST is again disconnected owing to the short circuiting of the relay Fcaused thereby.

In position 5 of the side switch the test relay K is connected to thelead 01 of the wanted subscribers line: earth, battery, winding of relayT1, lead 01, subscribers contact tn, wiper [0e26, side switch arm II inposition 5, windings III and II of the relay K, earth. If the wantedsubscriber is free, relay T1 and the relay K operate in this circuit.The energizing of the relay T1 causes the wanted subscribers line to bedisconnected in known manner from the common calling relay (not shown)and he cannot initiate a call. The testing operation is performed soquickly that the side switch maglll net may be again energized at oncein position 5 over its arm I and move the side switch into position 6,in which it is disconnected in known manner. The side switch is soconstructed that its wipers do not leave one set of contacts until afterengaging with the next, hence the movement of the side switch fromposition 5 to position 6 does not break the circuit over the relays Kand T1. The winding III ofthe relay K is disconnected in the position 6of the side switch, so that the relay K is maintained energized only byits winding II. Hence if any other selector set on this line, thecorresponding relay K will. be unable to energize owing to the drop ofpotential occasioned by the low resistance of winding II of relay K. Therelay K again connects up the relay F: earth, battery, resistance we,Winding of the relay. F, side switch arm III in position 6, double frontcontact k5, winding II of the relay K, earth, so that theside switch ismoved into the position 7 in the manner pre viously described. The relayT1 remains energized in the following circuit: earth, winding of therelay U, side switch arm II in position 7 wiper ka26, contactrtn, relayT1, battery, earth. The relay U however is not energized in this circuitowing to the high resistance of the winding of relay T1. The relay Kreleases on its circuit being opened when the side switch leavesposition 6. In position 7 of the side switch, the relay F is againenergized in the circuit: earth, back contact' u28, side switch arm I inposition 7, winding of relay F, resistance 104, battery, earth, so thatthe side switch moves into the position 8. In position 8 the relayTliremains energized in the circuit: earth, front contact (120, sideswitch arm II in position 8 and over wiper M126 as before. In osition 8the relay F is energized over the ront contact a20 and side switch arm Vin position 8, whereupon the side switch moves into position 9.

In position 9 or" the side switch alternating current is set over thewanted subscribers line for the first call and his bell (not shown) isrung. This circuit extends from pole changer PIV, side switch arm III inposition 9, wiper [M24 a lead of subscribers line, subscribers bell 5,lead of his line, wiper Z0025, side switch arm IV in position 9, toearth. i/Vhen the slow interrupter LU closes its contacts, the relay Fis again energized over the side switch arm I in position 9, and theside switch is thereby moved on into position 10. In this position therelay L is energized: earth, battery, relay interrupter RUl, winding ofthe relay L, back contact i129, side switch arm V in position 10, earth.The relay interrupterrRUl causes the relay L, by alternately opening andclosing its front contact Z30 at certain intervals of time (e. g. every5 seconds) to transmit ringing current over the Wanted line: earth,battery, resistance 104 winding of relay F, side switch arm IV in p0sition l0, wiper M225, Z) lead, bell of the want ed party, a lead, wiper[0e24, side switch arm III in position 10, front contact Z30, polechanger PIV. The relay F is so constructed that it does not respond toringing current and hence does not now operate. As soon however as thewanted party takes down his receiver a direct current bridge iscompleted across the two sides of the line by way of the transmitter(not shown) and the relay F is operated in the circuit over the calledsubscribers loop and to earth at contact Z31. The encrgization oi therelay F effects the moving on of the side switch into position 11 in themanner previously described. In position 11 ot the side switch the relayL is disconnected and the speaking leads are switched through from thecalling to the wanted party over the side switch arms III and IV so thatthe transmitter of the wanted party receives .t'eed current over thewindings oi the relay A. The connection has now been completelyestablished and the conversation can commence.

On the termination of the conversation both subscribers hang up theirreceivers. The relay A is thereby tie-energized and by closing its backcontact a5l completes a circuit for the relay F as follows: back contact6151, back contact v50, side switch arm I in position 11, winding ofrelay F, resistance 104, battery, earth, so that the side switch nowmoves into position 1 (normal position). The release of relay'A alsocauses the relay C to release, whereupon the opening of the double frontcontact 016 causes the relay T- of the calling subscriber to release. Inposition 1 of the side switch the relay interrupter RU is connected tothe rotary magnet D1 of the switch LIV: earth, battery, Winding of therotary magnet Dl, wiper (Z2, contact segment d3 side switch arm I inposition 1, double back contact c8, relay interrupter RU, earth. Theswitch L W thereupon rotates its wipers until its wiper d2 leaves thesegment d3 and rests on its normal contact (Z4. The relay T1 of theWanted subscriber releases as soon as the front contact (1% opens. Theswitch AS remains in the position to which it has been set and can nowbe taken into use by another calling subscriber.

The arrangement according to the invention will now be described torreaching another exchange. It will be assumed that the callingsubscriber Tn desires a connection with a subscriber connected to anautomatic or other exhange not shown, which is completed over thecontact group VG. In that case the impulses transmitted by the callingsubscriber in position 4 of the side switch cause the wipers of theswitch LIV to be set on a contact in the contact group VG, for instancewiper b66226 may be set on contact @5132. In this case, relay V is notmaintained energized and when it releases the relay F is energized overthe back contact 422, and moves the side switch into position 5. In thisposition, if the line taken into use is free, relay K is energizedenergized in the following circuit: earth, battery, resistance 1033,back contact r34, lead 02, contact @932, wiper 701126, side switch armII in position 7, winding of relay U, earth. The relay U opens its backcontact 24 28, and thereby prevents the side switch moving on into thenext position. The relay U also by opening the contacts M17 and U18disconnects the feeding relay A. The resulting deenergization of therelay A also causes the relay G to release by the o iening of contact(019. Therelay T of the calling subscriber Ta is maintained energizedover the front contact U after contact 016 opens. Furthermore inposition 7 of the side switch, the a and 6 leads areswitched throughover the side switch arms III and TV.

When this occurs a circuit is established over the trunk line VL, VLlfor the relay S as follows: earth, battery, resistance @036, backcontact 7937, lead VL, wiper 706424, side switch arm III in position 7,wiper 7ca10,

lead a, subscriber s station Ta, lead 7), wiper hall, side switch arm IVin position 7, wiper 7ca25, lead VLI, winding of the relay S, backcontact 2238, earth. The relay S operates and at its contact 839connects the relay T2 in a circuit extending over the lead 02. The relay T2 operates and by opening its contact Z34 disconnects theresistance 1083 from the before described circuit. .The relay T2 alsoby-closing its contact Z40 connects up the rotary magnet D2 ofanon-numerical switch, e. ATV: earth, battery, relay interrupter IlU2,winding of the rotary magnet D2, back contact 7741, front contact 2540,earth. The switch ATV rotates its wipers 766642, 766643, 706644, step bystep and hunts for a free trunk line leading to an automatic or otherexchange. When the switch finds such a line, e. g. VL2, VL3, (:3, therelay P is operated in the following circuit: earth, battery, resist-,ance i045, lead 03, wiper 7x444, winding of the relay P, front contact2540, earth. The relay P by opening its back contact 7941, disconnectsthe rotary magnet D2 and by closing its front contact 1946 it shortcircuits one part of its own winding, thus marking the line taken intouse engaged to other subscribers. Over the line branches VL2 and V113the connecting up of a calling relay (manual or semiautomatic exchange)of a bridging relay (automatic exchange) located at the distant exchangeis effected in known manner and by this means signalling devices oradditional switches responsive to number impulses can be controlled. Byclosing its front contacts p47 and p48,- the relay P connects thecalling line through and the calling subscriber is no tified in theusual manner e. by a buzzer signal that the line has been switchedthrough and that he may now transmit further impulses for operating theswitches in the other exchange required for completing the wantedconnection. In this case the feeding current for both the called andcalling lines is provided from the distant exchange.-

When the calling party hangs up his receiver at the end of theconversation, the relay S is released, and this by opening its con tacts39 opens the circuit of the relay T2. The release of the relay T2causes the relay U in series with it also to release. hen this occursthe relay F is energized over the back contact 1428 and the side switcharm I in position .7 so that the side switch is moved on into position8. In this position the relay interrupter RU is connected to the rotarymagnet of the switch LW: earth, battery, winding of the rotary magnetD1, wiper (72, contact segment (73, side, switch arm I in position 8,double back contact 08, relay interrupter RU, earth. The switch wipersare now rotated until the wiper d2 leaves the contact segment (73 andreaches the normal contact (74. WVhen the return movement of the switchLVV has been completed, the following circuit for the relay K isestablished: eartl1,'batte1'y, rotary magnet D1, wiper (72, normalcontact (74, winding of the relay K, side switch arm IV in position 8-,earth. The rotary magnet D1 of the switch LIV cannot operate inthis'circ-uit owing to the resistance 2049 inserted therein. The re layK however operates and by closing its double front contact 705establishes the following circuit: earth, resistance 104, winding of therelay F, side switch arm III in position 8, double front contact 765,winding II of the relay K, earth. The side switch therefore moves intothe position 9, whereupon the relay K releases. In position 9 of theside switch the relay F is again energized over the side switch arm Iand the slow interrupter LU so that the side switch is moved into theposition 10. In this position the relay F is energized over the backcontacts 4150, c451, and the side switch arm I, causing the side switchto move into the position 11 and thence on into the normal position 1.As already mentioned, the switch AS remains in the position in which ithas been set. The opening loo of the front contact 1635 caused therelease of the relay T of the calling subscriber.

What I claim and desire to protect by Letters Patent is 1. In atelephone system, an automatic switch, subscribers lines and trunk linesterminating in the banks of said switch, a set of wipers for said switchadapted to be moved in one direction only, means responsive to impulsessent to said switch for moving said wipers into engagement with the setof bank contacts corresponding to the number of impulses sent, saidmeans including a sideswitch, and means for determining the extent ofoperation of said side switch depending on whether said Wipers arepositioned on 'the contacts terminating a subscrihers line or a trunkline.

2. In a telephone system, an automatic switch, subscribers" lines andtrunk lines terminating in the banks of said switch, a set of wipers forsaid switch adapted to be moved in one direction only, means responsiveto impulses sent to said switch for moving said wipers into engagementwith the set of bank contacts corresponding to the number of impulsessent, said means including a side switch, a relay in said automaticswitch for controlling the extent of operation of said side switch, andmeans for operating said relay in case said wipers are moved intoengagement with a set of bank contacts terminating a trunk line.

3. In a telephone system, an automatic switch, subscribers lines andtrunk lines terminating in the banks of said switch, a set of wipers forsaid switch adapted to be moved in one direction only, means responsiveto impulses sent to said switch for moving said wipers into engagementwith the set of bank contacts corresponding to the number of impulsessent, said means including a side switch, means for causing the fulloperation of said side switch when said wipers are positioned on a setof bank contacts terminating a subscribers line, and means forpreventing the full operation of said side switch when said wipers arepositioned on a set of contacts terminating a trunk line.

4. In a telephone system, an automatic switch, subscribers lines andtrunk lines terminating in the banks of said switch, a set of wipers forsaid switch adapted to be moved in one direction only, means responsiveto impulses sent to said switch for moving said wipers into engagementwith the set of bank contacts corresponding to the number of impulsessent, said means including a side switch, means for partially operatingsaid side switch when said wipers are positioned on a set of contactsterminating a trunk line, and means for fully operating said side switchto initiate the restoration of said switch to normal when thesubscribers involved in the connection replace their receivers.

5. In a telephone system, an automatic switch, subscribers lines andtrunk lines terminating in the banks of said switch, a set of wipers forsaid switch adaptedto be moved in one direction only. means responsiveto a pluralitv of series of impulses sent to said switch for moving saidwipers into'engagement with a certain set of bank contacts de pending onthe number of series of impulses and the number oi impulses in eachseries sent, said means including a side switch, and means fordetermining the extent of operation of said side switch depending onwhether said wipers are positioned on the contacts terminating asubscribers line or a trunk line.

6. In a telephone system. a connector, trunks and lines promiscuouslyinterspersed in the banks of said connector, means responsive to one ormore series of impulses sent to said connector for operating the connector to connect with any of said lines or any of said trunks dependingon the total number of impulses sent, means operative when a line isconnected with for proiecting signalling current on the connected line,and means operative when a trunk is connected with for disabling saidlast means.

7. In a telephone system, a group of connectors, a group of subscriberslines accessible in common to all of said connectors, a group of trunks,a different one of said trunks being accessible to each of saidconnectors, 21 non-numerical switch terminating each of said trunks, andanother group of trunks accessible in common to all of said non-numerical switches.

8. In a telephone system, a group of trunks, a group of non-numericalhunting switches having their bank contacts multiply connected to saidtrunks, a group of subscribers lines, and a group of connectors havingcertain bank contacts multiply connected to said subscribers lines andhaving certain other bank contacts promiscuously interspersed with saidfirst certain bank contacts and individually connected to separate onesof said hunting switches.

In testimony whereof I afiEiX my signature.

ADOLF IVASCHNACK,

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